Archive for 2018

Publication of Technical Report 2018 Diever 450

Sunday, November 11th, 2018 No Comments

In light of the recent construction of a Diever windmill in South Africa, we have decided to publish a new Technical Report to describe recent developments and provide suggestions for further improvements. The TR2018 serves at once as a construction guide and as a comprehensive source of technical information on the Diever 450 windmill, supplementing the construction drawings.

The report can be obtained here.

The Technical Report 2018 was written by Chris Vos for the Working Group on Development Techniques (WOT), located in Enschede, The Netherlands. It replaces the Technical Report 1990 by Frans Brughuis which deals with an older version of the Diever 450.

Recent work done on the Diever prototype located on the WOT test terrain is described in the TR2018; this especially concerns the transmission and bearings. Many further improvements are suggested, including an improved rotor design, addition of counterweights to improve starting behaviour as well as more easily constructed foundation blocks. A completely new Diever design is also presented which completely consists of galvanised steel components.

Whoever wishes to start construction on their own Diever windmill is invited to contact the WOT to obtain construction drawings. The volunteers at WOT are more than willing to provide further advice where needed.

The Diever 450 is a water pumping windmill for use with deep wells in developing countries. The design has an Intermediate Technology character and use of advanced machinery is avoided. Main axle height is 10,5 meter and the mill is easily erected using a winch or tractor; when disassembled it can be transported on a Land Rover. Dievers have been built in a number of different countries, from Boliva to Nepal, and remain a reliable way of water supply all over the globe.

Maintenance Wooden Handpump

Thursday, September 6th, 2018 No Comments

For some time now the wooden pump frame has been in a bad condition. Due to this pumping was not possible anymore. After a long time of lying around, this summer the components of the pump were dusted off and the renovation was a fact. Most of the wood was rotten and had to be replaced, although some components could be re-used. Nevertheless the renovated pump wasn’t to be as colourful as the old version, so the components that had not rotten still had to be cleared from their old coating. Instead of paint, the wood would now be stained. The steel piping and base plate also required some work, and were repainted in a colour best described as british racing green, or simply darkish green. With the use of the construction manual and old pictures the frame was assembled.

But before all this, the pump itself had to be checked and mounted. It turned out that the top of the pumping rod was missing. Therefore a piece of rod was cut at the right length and mounted to the existing rod. At this moment the pump seemed to be complete, and assembly of the pump was the logical next step.

Nevertheless it was evident quickly that the pumping did not go well. The water that was collected seemed to be flowing back into the well, so that all the pumping effort was in vain. The pomp was drawn from the well, and opened up for inspection. In order to open the pump, it had to be dissected, a system that proved inconvenient. When the pump was opened the piston valve turned out to be jammed. As it was loosened it was free to move again. Another interesting observation was the large amount of sand and debris in the system, this explained the jamming of the valve. Besides this the components appeared to be alright. After the pump was cleaned of dirt the gauze at the bottom of the pump was replaced with a finer grid gauze so that less debris would be able to enter. After this the pomp was assembled in a more convenient way than previous, using steel plumbing parts so that the pumping tube could be easily mounted to the pump. Now, finally, the pump could be installed.

And it worked! The water was slightly dirty at the beginning, but this problem solved itself quickly. One drawback of the system however is the fact that the well empties quickly. Whether this is because the pump is to high in the well or whether the sublime renovation made the pump to good for the well, is still subject of discussion.

Introduction activities

Tuesday, August 28th, 2018 No Comments

  • Introduction evening
    1. Wednesday 12-9-2018

    Tour and dinner on our terrain at 18:00 with afterwards a drink.
    To join dinner please e-mail before 16:00.

  • Project evening
    1. Wednesday 19-9-2018

    Presentation about the current projects at the WOT.

  • Presentation WOT-member
    1. Wednesday 26-9-2018

    WOT-member Hilbert-Jan will be speaking about his experiences in Ethiopia.

  • Workweekend
    1. 29 and 30-9-2018

    A whole weekend of WOT-fun!

  • Course on workshop skills
    1. Wednesday 3-10-2018
  • Scrapheap Challenge
    1. Sunday 7-10-2018
  • Fix your own bike
    1. Wednesday 10-10-2018